Delay line instruments function to delay and/or apply a phase shift to electronic signals. An electronic signal may be delayed and/or phase shifted by a desired amount by causing the signal to travel some additional distance that corresponds to the desired delay. For example, trombone-style delay line instruments generally operate using a first conducting section that is slidably inserted into a second conducting section, such that sliding the sections apart increases the length of a signal path, and vice versa. U.S. Pat. No. 4,843,355 describes an arrangement in which inner and outer conductors of a cable length are received within cavities having electrically conductive inner walls. The conductors are electrically coupled to the cavity walls by toroidal springs which contact the cavity walls at their outer diameter. The cables are repositioned to achieve different desired amounts of signal delay.